Self-contained booster cylinder



Dec. 8, 1959 O. HRAMOFF SELF-CONTAINED BOOSTER CYLINDER Filed July 6. 1956 FIG. 2.

' LEGEND.

AIR OIL MOTION.

man PRESSURE AIR IN- (WORK STROKE) AIR EXHAUST.

(WORK STROKE) HIGH PRESSURE AIR m.

(RET/URN s'rnoxs) ATMOSPHERIC PRESSURE AIR IN-(RETURNSTROKE) AIR EXHAUST.

(RETURN STROKE) HIGH PREssuRE OIL m.

(woRK STROKE) OIL sxr-pgus-r.

( WORK STROKE) HIGH PRESSURE OIL IN.

(RETURN STROKE) OIL EXHAUST.

(RETURN STROKE) INVENTOR.

Olga Hramaff 2,915,878 SELF-CONTAINED BOOSTER CYLINDER Olga Hramolr, Bronx, N.Y. Application July 6, 1956, Serial No. 596,283 3 Claims. 01. 6054.5)

My invention relates to a new and useful improvement in the technique for boosting or increasing the pressure of a fluid medium. More precisely, this device takes a relatively low input air or hydraulic pressure, magnifies it manifold, and delivers this high output force to a working piston which is part of the original device.

The principal object of my invention is to provide a double acting cylinder capable of a low force approach stroke and a short, high pressure stroke, the high pressure stroke being many times greaterthan the product of input pressure and cylinder cross-sectional area.

A further object of my invention is to provide a cylinder as described above which will be less expensive to 'build and operate than a complete hydraulic system or an air operated booster system delivering the same output force at the same rates.

My invention consists of the novel parts in the com: bination and arrangement thereof, which are defined in the appended claims, and of which three embodiments are exemplified in the accompanying drawings, which are hereinafter particularly'described and explained.-

Throughout the description primed reference numbers are applied to the same member or to similar members of the different embodiments.

Figure 1 is a side elevation, partly in section, of the first embodiment, showing the pistons in their top-most position. This figure completely describes one variation of this invention.

Figure 2 is a side elevation, partly in section, of the second embodiment, showing the pistons in their topmost position. This figure completely describes a second variation of this invention. Figure 3 is a side elevation,

partly in section, of the third embodiment, showing the pistons in their top-most position. This figure completely describes a third variation of this invention.

Referring to Figure 1, it is seen that the upper section of the'cylinder contains piston '1 fastened to rod 2, the

assembly supported by spring 3. Rod 2 contains continuous oil passage 4, 5 and 6, which, in the position shown, connects the upper oil chamber A with the lower oil chamber B via oil channels 7 and 8. Piston 9 is free "to move along rod 2 and is supported in the position shown by the oil in chamber A. The; lower section of the assembly contains piston firmly connected to rod 11. Chambers A and B and passages 4, 5, 6, 7 and 8 are filled with oil via port 1'2.

With the device in the position shown, air under pres- F sure enters through port 13 and forces piston 9 to move down, transmitting pressure via the oil in chamberA and passages 4, 5, 6, 7 and 8 to chamber B and piston 10 forcing it to move down at the same rateas piston 9. Piston 1 remains stationary since the force exerted against it is not sufiicient to compress spring 3. Pistons 9 and 10, therefore, descend until rod 11 encounters resistance 14. The back pressure now created allows the air entering port 13 to compress and build up pressure in chamber A sufficient enough to overcome the Un St t s m? 0 2 resistance of spring 3 and force piston 1 to move down. The downward motion of piston 1 will force air from chamber C via passage 15 and misalign passages 6 and 7 prohibiting the transmission of pressure from chamber A to chamber B via the oil passages '4, 5, 6, 7 and 8.

The entire force developed by the air acting against pistons 9 and 1 will now be concentrated in area 16, creating a large increase in pressure in chamber B. The resulting force acting against resistance 14 will be seen to be equal to x x (FF) x d2 4 where;

D=inside diameter of cylinder d=diameter of rod 2 FF=friction and area factor p=inlet air pressure Applying air pressure to port 17 will raise back to the position shown in Figure 1.

Figure 2 is similar to the embodiment shown in Figure 1 with the exception that a common piston rod is used so that more accurate guidance of any load fastened to the piston rod may be achieved.

Referring to Figure 2, it is seen that piston 1' is now permanently fastened to tube 18, the assembly being supported by spring 3. Oil passages 19, 20, 21, 7' and 8' now connect oil chambers A and B. Air pressure entering the top of the cylinder at 13' forces piston 9 to displace oil from chamber A to B' via passages 19, 20, 21, 7 and 8, creating pressure on piston 10' which moves rod 22 down. Rod 22 moves down until encountering resistance 14. Pressure now builds up, in

the pistons chamber A sufiicient to overcome the resistance of spring down carries tube 18 and bushing 23 with it and increases the oil pressure in chamber B over chamber A by a factor approximately equal to t ri -d This increased pressure acts against piston 10' to greatly increase the force working against resistance 14'. Releasing theair pressure at port13 will allow spring 3' to relax and return channel 21 to alignment with channel 7. Air pressure entering port 17' will return the internal assembly to the position shown in Figure 2.

The embodiment illustrated inFigure 3 is identical to the device seen in Figure 1 with the exception that it is completely hydraulic and requires no initial oil fills. The output forces realizable with this device are greater by the ratio of input pressure thanthose realizable with the air-oil cylinder. 7 r

' The major dilference between the embodiment of Figure 3 and Figure 1 is that in Figure 3 piston 9 is omitted and oil entering port 13" flows to chamber B" via central oil channels 24, 6, 7" and 8". Chamber C" contains'air which is forced out through port 15" when piston 1" moves down.

All three variations of this invention have a relatively low pressure upstroke and can create high pressure only after encountering resistanceanywhere along the downstroke. These devices do not in anyway depend on gravity and can, therefore, be operated at any angle. Although not herein shown, the guide-rod-technique used with the pneumatic cylinder of Figure 2 can-be employed in the hydraulic variation of Figure 3. 7

, first endtplatecontaining an air connecting saidfirstair containing space toeither asource air if a a work stroke is require-d or,

g 'Ihis completesthe description of the illustrated embodiments. However, I wish it to be understood that my invention is not to be limited to the specific form Otjarrangement ;of parts herein described and shown; fijI claim: I v i a a 1' L A self contained booster cylinder assembly coma first chamber containing a first walls of the first chamber and is free to move relative to j said piston rod, a compression spring which wraps, around 1 said first piston rod andtpart;of said central bushing and is located between said first piston'and, said stationary disc, the space between saidfirstj and third pistons con taining an incompressible hydraulic fluid, passages in said firstpiston rod which in its initial or starting position are in exact alignment with said passages in said centralvbushing and which when external air pressureis brought to {bear upon said third piston, allows the free flow of said hydraulicfluid from said fluid containing space in said first chamber to said second chamber, a second piston and piston rod fastened to it in saidjsecond chamber which then moves underthe influence of said hydraulic i fluid,'said second piston being the work piston, cooperat- "in'g means existing between said first piston rod and said central bushing 'to block said oilv passages when said second piston rod encounters resistance to its movement: fanywhere alongits stroke, that means being the misalignment of said hydraulic fluid passages, said misalignment brought aboutby a relatively small movement of said first pistonrod, the length of which is small in disdance and is independent or; the stroke of said second serves as a guide-to'the movement of the aforementioned second piston, rod, said endplate containing an air -passage, said passage conne cting the air space formed between the aforementioned second piston and said end plate to either atmosphereifa work stroke is required or, a source of high pressure air if a return stroke is' required-,, a first end plate closing off the aforementionedv first ,chamber and forming, a first air containing space between itself and the. aforementioned .third piston, said of pressure atmosphere if a return stroke is required, and upon misalignment of said hydraulic; fluid passages,,presun1ing': a

work stroke'is in progress, further. movement, of. said' r. flow of hydraulic vfluid, a first chamber containing a first piston fastened to a piston rod, one end of said piston rod being guided by the-bushing centered within said stationary disc and the other end of said first piston rod 'guliding a third piston which is in turn guided by the walls of the first chamber and is free to move relative to said piston rod, a compression spring which wraps around said first piston rod and part'of said'central bushing andis located between said first piston and said stationary disc, the space between said first and third pistons containing an incompressible hydraulic fluid, said first pistonvrod containing an axial hole, said axial hole fitted at each end with bearings which serve to guide a second piston rod connected to a second piston, said second piston contained in said second chamber, said second piston rod smaller in diameter than said axial hole 7 in said first piston rod the diflerence in diameters between said second piston rod and said axial hole in' said first 1 piston forming: a clearance passage, said clearance pasa piston rod, said misalignment occurring after the hydraulic fluidpressure in said first chamber becomes large enough to overcome the resistance of said compression spring, a second end plate closing 05' the aforementioned second chamber except fora through bearing hole which sage connecting to passages in said first piston rod, said passages in said first piston rod in its initialor starting position: being. in exact alignment with said passages in said central bushing and which when external air pressure is brought to bear upon said third piston, allows the free flow of hydraulic fluid from said fluid containing space in said first chamber to said second chamber causing the movement of said second piston, said second piston being the work piston, said second piston rod extending a through bearings in a first end plate'closing off said first chamber and .forminga first air containing space between itselfand the aforementioned third piston, said first end plate containing an air passage, said am passage connecting said first air containing space to either a source of high pressure air if a work stroke is requ red or, atmosphere if a return stroke is required, a second end plate closing oflf said second chamber and forming a second air containing space between itself and the aforementioned second piston, said second end plate containing an air passage connecting said second aircontaining space to either atmosphere if a work stroke is required, or a source of highpressure air if a return strokeis required, hearings in each of the first and second end plates providing accurate guidanceof said second piston rod, cooperating means existing between 'said'first passage, said air' passage 7 second: piston. rod: against: its encountered resistance comeslas a result of: pressure applied tos'saidhydraulic fluid in said second chamber by said first piston rod, bringingabout-a multiplicationof specific hydraulic fluid ,workstroke'it will be necessaryto switch said first air passage in said first end plate to atmosphere and intro- -duce press'ureinto said second air passage in said second end' plate', inorder to move the aforementioned first, second-and third pistons back to" their initial or 7 startingpositions; V a 7 a a a V 2;' A self contained booster cylinderassembly "coma piston prising'two" chambers separatedbya stationarydisc and centralbushing, j said bushing beinggcentered within. the

stationary disc and containing passageways is new the piston rod and said central bushing .to block said oil passages when'said second piston rod encounters resist- .ance' to its movement anywhere along its stroke, that means being the misalignment of said hydraulic fluid passages, said misalignment brought about by a relatively small movement of said first piston rod, the length of whichis small 'infdistance and is independent of the stroke of said second piston rod, said misalignment occurring; after the hydraulic fluids pressure in said first chamber becomes largeenough to overcome the resistance of said compression spring. whereupon, after thisalignment'of said hydraulic fluid passages presuming a work stroke is, in'progress, further movement 'of said second piston rod against its encountered resistance comes as a result of pressure applied to' said hydraulic fluid in aboutra multiplication of specific hydraulic fluid pressure in said second chamber in the ratio of, said second piston area to said first piston rod; net: area.

3, self contained booster cylinder assembly comprising twochambers separated-by a stationary'disc and bushing, said bushing beinggcontained within the stationary ,of hydraulic fluid, a first chamber containing ;a first fastened toa piston-rod, one end of said piston rod: being-guided by the bushing centered within said stationary disc; .7 a compression; spring: which wraps around .firjst piston rod and part of said: central bushing and lstlocated between, said first piston rand said stationary 4 disc, a first end plate closingtolf: said first chambensaid saidsecondvchamber by said first piston rod; bringing disc and containing passageways to allow the flow containing a passage, said passage connecting 7 either a source of external hydraulic fluid pressure if a work stroke is required or a hydraulic fluid sink if a return stroke is required, to the space bounded by said end plate and said first piston, said space also containing hydraulic fluid, passages in said first piston rod which, in its initial or starting position are in exact alignment with said passages in said central bushing and thereby allows the flow of hydraulic fluid from an external source through the first fluid containing space to the second chamber, a second piston and piston rod fastened to it in said second chamber which will move under the in fluence of hydraulic fluid flow into said second chamber, said second piston being the work piston, cooperating means existing between said first piston rod and said central bushing to block said oil passages when said second piston rod encounters resistance to its movement anywhere along its stroke, that means being the misalignment of said hydraulic fluid passages, said misalignment brought about by a relatively small movement of said first piston rod, the length of which is constant and small in distance and is independent of the stroke of said second piston rod, said misalignment occurring after the hydraulic fluid pressure in said first chamber becomes large enough to overcome the resistance of said compression spring, a second end plate closing 01f the aforementioned second chamber except for a through bearing hole which serves as a guide to the movement of the aforementioned second piston rod, said end plate containing a hydraulic fluid passage, said passage connecting the space formed between said end plate and the aforementioned second piston to either a hydraulic fluid sink if a work stroke is required or, a source of hydraulic fluid pressure if a return stroke is required, said space being filled with hydraulic fluid, whereby, after misalignment of said hydraulic fluid passages in said first piston rod and central bushing further movement of said second piston rod against its encountered resistance comes as a result of pressure applied to said hydraulic fluid contained between said second piston and said stationary disc in said second chamber, by said first piston rod, bringing about a multiplication of specific hydraulic fluid pressure in said second chamber in the ratio of said second piston area to said first piston rod area whereupon, after the cylinder has performed a work stroke or part of a work stroke, it will be necessary to externally switch the fluid passage in said first end plate to a hydraulic fluid sink and introduce hydraulic fluid pressure into said second hydraulic fluid passage in said second end plate in order to return the aforementioned first piston and second piston back to their initial or starting position.

References Cited in the file of this patent UNITED STATES PATENTS 791,075 Carpenter May 30, 1905 2,169,423 Kessler et al. Aug. 15, 1939 2,173,583 Forichon Sept. 19, 1939 2,603,067 Nissim July 15, 1952 FOREIGN PATENTS 929,959 France July 28, 1947 

